US11557411B2 - Grain boundary engineering of sintered magnetic alloys and the compositions derived therefrom - Google Patents

Grain boundary engineering of sintered magnetic alloys and the compositions derived therefrom Download PDF

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US11557411B2
US11557411B2 US16/073,521 US201716073521A US11557411B2 US 11557411 B2 US11557411 B2 US 11557411B2 US 201716073521 A US201716073521 A US 201716073521A US 11557411 B2 US11557411 B2 US 11557411B2
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Miha Zakotnik
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Noveon Magnetics Inc
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    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
    • H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
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    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
    • H01F41/0293—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets

Definitions

  • the present disclosure is directed at methods of preparing rare earth-based permanent magnets and the magnets arising from these methods having improved magnetic properties.
  • Particular embodiments include alloys comprising neodymium-iron-boron magnets, including grain boundary engineered Nd 2 Fe 14 B magnets.
  • Neodymium, Iron, Boron (NdFeB) magnets were first developed in the early 1980s and are now among the most important permanent magnetic materials currently in production. These magnets are used in a wide range of applications, such as MRI machines, hard disk drives, loudspeakers, linear motors, A/C motors, wind turbines, hybrid electric vehicles, elevator motors, and mobile phones and other consumer electronics.
  • Dy dysprosium
  • Tb terbium
  • NdFeB materials require a high concentration of Dy or Tb elements to form the highly coercive sintered NdFeB magnet bodies that are able to operate at high temperatures.
  • This conventional method of modifying properties has associated high material and processing costs.
  • This process is said to reduce the amount of Dy or Tb required to create a high coercivity magnet suitable for motor applications.
  • grain boundary diffusion is limited to magnets with a body not exceeding 6 mm in thickness and requires additional post processing steps and complex and expensive machinery to execute successfully.
  • diffusion processes limit the extent to which coercivity can be increased; typically only a 30-40% increase in coercivity is achieved using this process.
  • the present disclosure is directed to solving at least some of these problems.
  • the present disclosure describes a method of making useful rare earth magnets operable at high temperatures, and the magnets thereby produced.
  • Certain embodiments provide methods of preparing a sintered magnetic body having improved coercivity and remanence, each method comprising:
  • the mixed alloy particles may be characterized as the second core alloy particles comprising a first GBM alloy coating, either as a particulate coating (i.e., in the composite alloy preform) or continuous or semi-continuous (i.e., in the discrete mixed alloy particles) coating.
  • the homogenizing step (a) is preceded by treating coarse particles of either the first GBM or second core alloy or both the first GBM and second core alloys with hydrogen gas under conditions and for a time sufficient to allow absorption of the hydrogen into either or both of the alloys.
  • This hydrogen treatment step may be followed by an outgassing treatment step.
  • the methods further comprise: (c) compressing the population of mixed alloy particles together to form a green body, in the presence of a magnetic field of a suitable strength to align the magnetic particles with a common direction of magnetization, preferably in an inert atmosphere.
  • Additional embodiments include those methods further comprising (d) heating the green body to at least one temperature in a range of from about 800° C. to about 1500° C. for a time sufficient to sinter the green body into a sintered body comprising sintered core shell particles and a grain boundary composition.
  • the methods further comprise (e) heat treating (or annealing) the sintered body in an environment of cycling vacuum and inert gas.
  • the temperature of the cycling environment is in the range of from about 450° C. to about 600° C.
  • the sintering/sintered body is magnetized by applying a magnetic field of sufficient strength to achieve final remanence and coercivity as described herein, for example, using a magnetic field in a range of from about 400 kA/m to about 1200 kA/m (0.5 to 1.5 T).
  • the first GBM alloy is substantially represented by the formula AC b R x Co y Cu d M z , present either by itself or as a coating on the second core alloy particles where:
  • the first GBM alloy is substantially represented by the formula Nd j Dy k Co m Cu n Fe p , where
  • j is atomic percent in a range from 1 to 2, 2 to 3, 3 to 4, 4 to 5, 5 to 6, 6 to 7, 7 to 8, 8 to 9, 9 to 10, 10 to 11, 11 to 12, 12 to 13, 13 to 14, 14 to 15, 15 to 16, 16 to 17, 17 to 18, 18 to 19, 19 to 20 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • k is atomic percent in a range from 1 to 5, 5 to 10, 10 to 15, 15 to 20, 20 to 25, 25 to 30, 30 to 35, 35 to 40, 40 to 45, 45 to 50, 50 to 55, 55 to 60 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • m is atomic percent in a range from 1 to 5, 5 to 10, 10 to 15, 15 to 20, 20 to 25, 25 to 30, 30 to 35, 35 to 40, 40 to 45, 45 to 50, 50 to 55, 55 to 60 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • n is atomic percent in a range from 0.1 to 0.5, 0.5 to 1, 1 to 1.5, 1.5 to 2, 2 to 2.5, 2.5 to 3, 3 to 3.5, 3.5 to 4, 4 to 4.5, 4.5 to 5, 5 to 5.5, 5.5 to 6, 6 to 6.5, 6.5 to 7, 7 to 7.5, 7.5 to 8, 8.5 to 9, 9 to 9.5, 9.5 to 10, 10 to 12, 12 to 14, 14 to 16, 16 to 18, 18 to 20 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • p is atomic percent in a range from 1 to 2, 2 to 3, 3 to 4, 4 to 5, 5 to 6, 6 to 7, 7 to 8, 8 to 9, 9 to 10, 10 to 11, 11 to 12, 12 to 13, 13 to 14, 14 to 15, 15 to 16, 16 to 17, 17 to 18, 18 to 19, 19 to 20 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • j, k, m, n, and p are independently variable within their stated ranges provided that the sum of j+k+m+n+p is greater than 95, 96, 97, 98, 99, 99.5, 99.8, or 99.9 atom % to about 99.9 atom % or 100 atom %.
  • the disclosure is not limited to methods of processing, and in some embodiments provide for the particles, green bodies, or sintered bodies prepared by the disclosed methods, as well as articles and devices comprising these sintered bodies.
  • compositions comprising a GBM alloy, wherein this alloy is substantially represented by the formula: AC b R x Co y Cu d M z , wherein:
  • (A) AC comprises Nd and Pr in an atomic ratio in a range of from 0:100 to 100:0, and b is a value in a range of from about 5 atom % to about 65 atom % or from 10 atom % to about 50 atom %;
  • R is one or more rare earth element and x is a value in a range of from about 10 atom % to about 60 atom %;
  • (D) y is a value in a range of from about 30 atom % to about 40 atom %;
  • (E) d is a value in a range of from about 0.01 atom % to about 6 atom %;
  • (F) M is at least one transition metal element, exclusive of Cu and Co, and z is a value in a range of from about 0.01 atom % to about 10 atom %;
  • the composition contains less than 0.1 wt % oxygen or carbon.
  • the GBM alloy may comprise one or more phases that are amorphous or in a form containing columnar and globulite crystals.
  • the disclosure also describes an apparatus for mixing particles, the apparatus comprising:
  • the disclosure also provides a system for processing the inventive method and compositions; the system comprising the apparatus for mixing particles and further comprises one or more of:
  • a rotatable hydrogen reactor capable of treating magnetic materials with hydrogen at pressures in a range of from about 1 to about 10 bar (or in some circumstances, higher);
  • a compression device capable of applying a force in a range of from about 800 to about 3000 kN (per 20 cm 2 , or 60 MPa) to a population of particles, the compression device fitted with a source of a magnetic field capable of providing a magnetic field in a range of from about 0.2 T to about 2.5 T, while the compression device is applying the pressure to the population of particles;
  • a sintering chamber configured to provide alternative vacuum and inert atmosphere environments within the chamber while providing an internal temperature to the chamber in a range of from about 400° C. to 1200° C.
  • the system comprises any 2, 3, 4, or 5 of the elements (a) to (e).
  • FIG. 1 shows a theorized schematic of one embodiment of a GBE-NdFeB based microstructure, containing the multiple shells surrounding a G 2 Fe 14 B based hard magnetic phase, where G is a rare earth element, for example Nd.
  • FIG. 2 shows some physical forms of GBM alloy materials: (A) shows a form of the GBM alloy and (B) shows examples of strip cast flakes.
  • FIG. 3 shows one exemplary process flow diagram, highlighting various options for manufacturing Grain Boundary Modifying (GBM alloys) and the various processing stages where the GBM alloy can be added to strip cast flakes to make an exemplary GBE-NdFeB magnet.
  • GBM alloys Grain Boundary Modifying
  • FIGS. 4 A-B shows two demagnetization loops for a conventionally sintered strip cast magnet and a GBE-NdFeB magnet, labeled as Magnet and GBE Magnet respectively.
  • the weight ratio is S1 (97.7):A2 (2.3). See Table 2.
  • the weight ratio is S1 (97.2):A1 (2.8).
  • FIG. 5 shows a backscattered SEM image of a GBM Alloy, based on the composition of Nd 8.93%, Pr 3.05%, Dy 21.13%, Tb 21.60%, Co 38.33%, Cu 5.33% Fe 1.28%, and Zr 0.62% by atom percent, the different contrast levels show the GBM Alloy to consist of multiple phases. See Table 10 for explanations of phases 1 , 2 , and 3 .
  • FIG. 6 shows an exemplary powder XRD pattern for a representative first GBM alloy (see, e.g. Table 3).
  • FIG. 7 shows an exemplary powder XRD pattern for a representative second GBM alloy (see, e.g. Table 4).
  • a first GBM alloy is used to modify a second core alloy.
  • the steps for accomplishing this includes reducing the size of the first GBM and second core particles to specific dimensions, the sizes being suitable for coating (or more generally admixed) micro-grains of the second core (magnetic) alloy with particles of a first GBM alloy.
  • Subsequent steps comprising powder metallurgy and heat treatments provide conditions in which the elements of the first GBM alloy are allowed to diffuse into the grains of the second core alloy, providing a core shell structure, the core comprising and retaining a hard magnetic phase of the second core alloy.
  • Magnetization and further heat treatments post sintering allow for additional control of the magnetic character of the resulting sintered bodies.
  • high energy rare earth magnets including GBE-NdFeB magnets that have high, uniform coercivity that are resistant to demagnetizing fields and corrosion, with improved thermal stability, whilst using low levels of expensive rare elements in their manufacture.
  • compositions and methods of making and using refer to compositions and methods of making and using said compositions. That is, where the disclosure describes or claims a feature or embodiment associated with a composition or a method of making or using a composition, it is appreciated that such a description or claim in one context is intended to extend these features or embodiment to embodiments in every other of these contexts (i.e., compositions, methods of making, and methods of using).
  • transitional terms “comprising,” “consisting essentially of,” and “consisting” are intended to connote their generally in accepted meanings in the patent vernacular; that is, (i) “comprising,” which is synonymous with “including,” “containing,” or “characterized by,” is inclusive or open-ended and does not exclude additional, unrecited elements or method steps; (ii) “consisting of” excludes any element, step, or ingredient not specified in the claim; and (iii) “consisting essentially of” limits the scope of a claim to the specified materials or steps “and those that do not materially affect the basic and novel characteristic(s)” of the claimed invention.
  • Embodiments described in terms of the phrase “comprising” also provide, as embodiments, those which are independently described in terms of “consisting of” and “consisting essentially of.”
  • the basic and novel characteristic(s) is the ability to prepare the inventive magnetic materials (or the magnetic materials themselves) using or comprising the materials described in those embodiments, yet allowing for the optional presence of impurities or other additives that have little or no additional or adverse effect on the magnetic properties of the resulting materials.
  • the reference to the genus “rare earth elements” not only includes any individual or combination of two or more elements within that genus (including, e.g., La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu), but also includes, as specific embodiments, the general genus exclusive of one or more of the elements of that genus (e.g., Sm), even if each member of the genus is not specifically recited as excluded.
  • the general genus exclusive of one or more of the elements of that genus e.g., Sm
  • NdFeB refers to a composition comprising neodymium, iron, and boron, at least a portion of this being of the stoichiometry Nd 2 Fe 14 B.
  • GEB-NdFeB refers to a composition of comprising Nd 2 Fe 14 B (or “NdFeB”) which have been prepared by so-called Grain Boundary Engineering (“GBE”) to incorporate Grain Boundary Modifiers (“GBMs”) so as to provide “Grain Boundary Engineered compositions” (“GBE compositions”).
  • GBE or Grain Boundary Engineering refers to a process by which particles comprising NdFeB, and structures prepared from such particles, reacted with particulate alloys, described as Grain Boundary Modifier (or Modifying) alloys (or “GBM alloys”) such that when sintered together, the particular metals associated with the particulate alloys migrate into the bodies of the NdFeB particles, while forming a matrix for the grains, to form “GBE magnets” (“Grain Boundary Engineered magnets”).
  • GBM alloy metals into the NdFeB particles result in core-shell structures, where the resulting core shell particles may be characterized, for example, as depicted in FIG. 1 ; that is, comprising a core of the original Nd 2 Fe 14 B particle, and gradients of the various alloy metals distributed through the core-shell particle.
  • homogenizing refers to a process of mixing under conditions suitable for preparing a uniform distribution of particles, resulting in a composition that is “substantially homogeneous.” The process of homogenizing also results in the attrition of some or all of the particles. While perfect uniformity (i.e., pure homogeneity) may be a desirable goal, the term “homogenizing” does not necessarily result in such perfect uniformity.
  • a resulting composition may be considered “substantially homogeneous,” to reflect the practical considerations of mixing powders, if at least three samples are taken and tested, for example by ICP, and the results of the three analyses are within some predetermined target precision range (e.g., standard deviation of material measurements less than 5, 3, 2, 1, 0.5, or 0.1%, preferably less than 0.5 or 0.1%%, relative to the mean) or within 0.1% to 0.5% of the target value for the component.
  • target precision range e.g., standard deviation of material measurements less than 5, 3, 2, 1, 0.5, or 0.1%, preferably less than 0.5 or 0.1%%, relative to the mean
  • solidus temperature confers its ordinary meaning of the temperature below which the substance is completely solid (crystallized).
  • substantially represented by the formula” X refers to an alloy having a nominal formula X, but allowing for the presence of minor levels of impurities or deliberately added dopants.
  • mixed alloy refers to a composition in which the second core alloy particle is in contact with, and preferably at least partially coated with, particles of the first GBM alloy. Depending on the heat treatment experienced by the mixed alloy, some or none of the elements of the first GBM alloy may be diffused into the particles of the second core alloy.
  • Green body carries its normal connotation in the contact of pre-sintered objects.
  • ranges are provided, it is intended that every integer or tenth of an integer, within the range represents an independent endpoint (either minimum or maximum value) in the same range.
  • the term “is greater than at least one of” a series of values is intended to connote that each of the series of values are independent embodiments. Further, in cases where a sum of values is described as greater than one or more values (e.g, “greater than at least one of 95, 98, 99, 99.5, 99.8, or 99.9 atom %”) it should be apparent that the sum of does not exceed 100 atom %.
  • a description of “greater than at least one of 95, 98, 99, 99.5, 99.8, or 99.9 atom %” also includes separate embodiments where the sum is in a range of from 95 to 98, 98 to 99, 99 to 99.5, 99.5 to 99.8, 99.8 to 99.9, 99.9 to 100 atom %, or any combination of two or more of these ranges. Any nominal difference from 100% may be attributable to accidental impurities or other deliberately added dopants, including from main group elements, such as Al, C, Si, N, O, or P.
  • This disclosure refers to chemical compositions, both bulk with respect to homogeneous or substantially homogeneous alloys and powders and with respect to compositions within a particle or grain or within or across a grain boundary.
  • the embodiments describing these compositions implicitly describe the methods used to measure the quality or properties of these compositions.
  • the embodiment described can be read as that composition having been identified by an appropriate method including, for example, Inductively Coupled Plasma (“ICP”).
  • ICP Inductively Coupled Plasma
  • an embodiment can be read as that composition having been identified or characterized using Energy dispersive X-ray Spectroscopy (“EDS”) mapping across a fractured or polished surface comprising that particle, grain, or grain boundary.
  • EDS Energy dispersive X-ray Spectroscopy
  • the samples may be prepared for analysis by (gently) polishing the surface(s) using a 1200 grinding paper comprising SiC before inserting them into the SEM for EDS analysis.
  • the surface(s) may be polished using a diamond paste and rinsed. Once in the SEM, and prior to the EDS analysis, the surface is or may be cleaned with Ga Ions to ensure a clean and oxygen-free surface.
  • Various embodiments of the present disclosure include methods of preparing sintered magnetic bodies having improved coercivity and remanence, each method comprising:
  • the mixed alloy particles may be characterized as the second core alloy particles comprising a first GBM alloy coating, either present as a particulate coating (i.e., in the composite alloy preform) or as a continuous or semi-continuous (in the discrete mixed alloy particles) coating.
  • the coating of the first GBM alloy has a coating thickness in a range of from 0.05 to 0.1, from 0.1 to 0.15, from 0.15 to 0.2, from 0.2 to 0.25, from 0.25 to 0.3, from 0.3 to 0.35, from 0.35 to 0.4, from 0.4 to 0.45, from 0.45 to 0.5 microns, or a range combining two or more of these ranges; for example, from 0.1 to 0.25 microns.
  • the homogenizing step (a) is preceded by treating coarse particles of either the first GBM or second core alloy or both the first GBM and second core alloys with hydrogen under conditions and for a time sufficient to allow absorption of the hydrogen into either the first GBM or second core alloy or both the first GBM and second core alloys.
  • Such embodiments allow for the use of alloy forms that are conveniently prepared albeit in large particle or flake form.
  • the methods further and independently comprise: (c) compressing the population of mixed alloy particles together to form a green body, under a magnetic field of a suitable strength to align the magnetic particles with a common direction of magnetization in an inert atmosphere; (d) heating the green body to at least one temperature in a range of from about 800° C. to about 1500° C. for a time sufficient to sinter the green body into a sintered body comprising sintered core shell particles and a grain boundary composition; and (e) heat treating (or annealing) the sintered body in an environment of cycling vacuum and inert gas, optionally in the presence of a magnetic field.
  • the methods of the present disclosure are particularly suitable for mixing multiple metals with particles of the second core alloy to provide more uniform and homogeneously distributed particles of discrete mixed alloy particles.
  • the first GBM alloy may comprise at least 3, 4, 5, 6 or more rare earth or transition metals, providing for the stoichiometrically precise addition of these metals to the second core alloy. This provides a much more convenient and reproducible means of adding such materials, relative to the addition of separate powders for each individual element.
  • the present methods rely on the initial intimate metallurgical mixing of the particles to provide the mixed alloy (pre-sintered) particles.
  • This intimate mixing provides for the ability to produce substantially homogeneously constructed sintered bodies of superior performance using less expensive additives.
  • the first GBM alloy made be considered to be a pre-grain boundary material (e.g., the GBM alloy ultimately forms a grain boundary material) and the second core alloy considered to be the core-shell particle precursor (e.g., at least a portion of the second core alloy ultimately forms the core of the core-shell particle).
  • Nd 2 Fe 14 B may be seen as one convenient embodiment of this second core alloy, though in neither case is the disclosure limited to these exemplars or descriptions, nor do these characterizations limit the compositions to those applications.
  • the GBM alloys may be prepared by methods including induction casting, strip casting, or atomized powder methods (see Examples).
  • the second core alloy is a hard magnetic alloy produced, in some implementations by traditional strip casting or by recycling existing rare earth metal magnets. The elements are combined in these alloys as non-oxides, and the reactions done in the substantial absence of oxygen (i.e., taking deliberate steps to avoid the introduction of air or oxygen during processing, for example by processing the alloys under inert atmospheres.
  • the first GBM alloy should be comprised of a combination of AC, R, Co, Cu, and M in the recited proportions so as to be capable of forming an alloy or intermetallic compound both with itself and with the second core alloy.
  • the first GBM alloy is typically more friable than the second core alloy, which is typically much harder, allowing for requisite processing.
  • the first GBM alloy has a lower melting point than the second core alloy, or at least is more susceptible to its elements migrate into the second core alloy than vice versa.
  • the methods are described in terms of pre-treating coarse particles of either the first GBM or second core alloy or both the first GBM and second core alloys in the presence of hydrogen under conditions and for a time to allow absorption of the hydrogen into either the first GBM alloy or second core alloy or both the first GBM alloy and second core alloys, prior to the homogenizing step (a).
  • Such hydrogen treatments may comprise treating the respective alloy(s) to hydrogen pressures from 0.1 bar to 150 bar, preferably from 1 bar to 10 bar.
  • the term “coarse” in terms of particle size may be defined in terms of any size larger than ten microns (in any aspect direction), the term may also reflect the use of starting materials derived from induction casting, strip casting, or atomized powder methods of preparing the bulk alloys.
  • the material forms typically provided to the processes are flakes or pieces having dimensions on the centimeter scale.
  • the first (GBM) flake can have initial dimensions on the order of 5 cm ⁇ 5 cm ⁇ 7 cm (e.g., see FIG. 2 (A) ), and the second (e.g., an NdFeB) flake can have initial dimensions on the order of 0.2 cm ⁇ 2-6 cm ⁇ 2-8 cm (e.g., see FIG. 2 (B) ).
  • the thickness distribution of the strip cast flakes is Gaussian with a +/ ⁇ 2.5% standard deviation tolerated around the mean value.
  • the GBM flake initial dimension has a Gaussian distribution as well with a 5% accepted variability across the identified dimensions.
  • the hydrogen treatments may be followed by an outgassing treatment, for example at temperatures in a range of from about 200° C. to about 850° C. or from about 400° C. to about 600° C., but less than the melting temperature of the first GBM alloy.
  • This cycling of hydrogen absorption and desorption is a convenient and effective means for destabilizing the initial flakes or chunks, making them more susceptible to pulverization during the homogenization stage.
  • NdFeB magnets are composed of two main phases; a magnetic grain, crystal or core phase composed of Nd 2 Fe 14 B, surrounded by a thinner Neodymium (Nd) rich phase that ‘coats’ each core grain and is known as the ‘grain boundary.’
  • Nd Neodymium
  • the surface area of the core grain phase is increased via a series of selective decrepitation and milling steps that break the large core phases, present in the newly strip cast NdFeB alloy, into smaller crystals and/or particles without destroying their intrinsic magnetic potential. This typically results in recovery of ⁇ 95% of the mass of Nd 2 Fe 14 B but this material is now present as a much larger number of tiny cores or grains.
  • the homogenizing step (a) may comprise multiple separate mixing steps, which increases the average surface area of at least one, preferably both, of the particle populations.
  • three such mixing steps are used: the first to initiate composition shift within the mixture; the second to uniformly distribute the first GBM alloy with the second core alloy by increasing the surface area; and the third to achieve a final, targeted composition of the mixture.
  • Exemplary processing includes the simultaneous mixing and heating to retain particulate form.
  • the temperatures used during mixing can be and preferably are cycled between at least first and second temperatures, the first temperature being about ambient (in a range of about 23° C. to 30° C.) and second temperature being in a range of from about 75° C. to about 125° C., preferably 80° C.
  • the two powders are mixed in a rotating mixer, for example being rotated for at least 50 or 60 minutes at 30 to 60 revolutions per minute to produce a substantially homogeneous composition.
  • FIG. 3 See also FIG. 3 for a schematic representation of exemplary steps available for use in such processes and the Examples for representative methods.
  • the homogenizing/mixing steps are effected with the first and second particles as dry particles by tumbling in one or more rotating mixing chambers.
  • the homogenizing/mixing steps are done by attrition milling, using attritor balls. In both cases, the walls of the chambers and/or the attritor balls should be of sufficient hardness, relative to the first and second alloy particles, so that there is virtually no material transfer from the former to the latter.
  • the methods are flexible both in terms of the options available for the chemical composition of the first GBM alloys, and also for the ratio of the first GBM and second core alloys.
  • the first population of particles of a first GBM alloy and the second population of particles of a second core alloy may be mixed in any weight ratio combination from 0.1:99.9 to 99.9:0.1, consistent with the final desired composition.
  • the relative amounts of the first and second alloys may be defined as ranging from 0.1 parts of the first alloy per 99.9 parts of the second alloy to 16.5 parts of the first alloy per 83.5 parts of the second alloy.
  • Additional independent embodiments include those incremental ratios of the first GBM alloy, including 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 1.5, 12, 12.5, 13, 13.5, 14, 14.5. 15, 15.5, 16, or 16.5 parts of the first alloy (per 100 parts of the final composition) are mixed with a complementary amount of the second core alloy. Any ratio of two of these values may comprise an independent embodiment, for example, from 6.5 parts first alloy to 93.5 parts of the second core alloy.
  • the purpose of the homogenizing steps are to provide substantially homogeneous mixed alloy powders, such that the GBM alloy particles can subsequently ‘coat’ the particles of the second core alloy (e.g., the Nd 2 Fe 14 B particles).
  • the second core alloy e.g., the Nd 2 Fe 14 B particles.
  • both Nd 2 Fe 14 B and bulk pieces of the proprietary alloy are milled to very fine particles ( ⁇ 3.8 micrometers).
  • the relative hardness and friability of the two materials typically results in particle sizes in which the particle sizes of the first GBM alloy are smaller than those of the second core alloy.
  • the mean particle diameter of the first population of particles of the first GBM alloy is in a range of from about 0.5 microns to about 5 microns, or any individual or combination of sub-ranges including from 0.5 to 0.8 microns, from 0.8 to 1 micron, from 1 to 2 microns, from 2 to 2.5 microns, from 2.5 to 3 microns, from 3 to 4 microns, or from 4 to 5 microns, or a range combining two or more of these ranges, for example 1 micron to 4 microns.
  • the mean particle diameter of the second population of particles of the second core alloy is in a range of from about 2 microns to about 5 microns. In some embodiments, this range may be from 2 to 2.2 microns, from 2.2 to 2.4 microns, from 2.4 to 2.6 microns, from 2.6 to 2.8 microns, from 2.8 to 3 microns, from 3 to 3.2 microns, from 3.2 to 3.4 microns, from 3.4 to 3.6 microns, from 3.6 to 3.8 microns, from 3.8 to 4 microns, from 4 to 4.2 microns, from 4.2 to 4.4 microns, from 4.4 to 4.6 microns, from 4.6 to 4.8 microns, from 4.8 to 5 microns, from 5 to 5.2 microns, from 5.2 to 5.4 microns, from 5.4 to 5.6 microns, from 5.6 to 5.8 microns, from 5.8 to 6 microns, or any combination of two or more of these ranges.
  • the resulting mixed alloy particles which may be envisioned as second core alloy particles coated with first GBM alloy particles, reflect the additive nature of the mixing, and in some embodiments, the mean particle of the population of discrete mixed alloy particles is targeted to be in a range of from about 2 microns to about 6 microns, preferably 3 to 4 microns.
  • the actual form of the mixed alloy particles depends on the heat treatment conditions and the specific nature of the first GBM alloy.
  • the first GBM alloy may be simply adhered to the second core alloy or may partially or completely coat the second core alloy, or the elements of the first alloy may have begun to migrate into the second core alloy particles. Any given mixture of these particles may contain one or more of these types of particles.
  • the composition of the particles is monitored during this processing using methods including the use of Inductively Coupled Plasma (“ICP”).
  • ICP Inductively Coupled Plasma
  • samples are taken from the mixing chambers during processing and tested by ICP. In each case, at least three samples are taken and tested, and the mixture is considered substantially homogeneous when the results of the three analyses are within some predetermined target range.
  • the particles are also tested for proper particle sizing, using a particle size analyzer, as are available for this purpose (see, e.g., Examples). If the compositions differ from the targeted compositions, adjustments may be made by the addition of particles of the first or second alloys, depending on the adjustments to be made to the compositions. If the particles sizes are too large, the mixing is continued.
  • the first GBM alloy comprises a composition stoichiometry of AC b R x Co y Cu d M z , where AC, R, M, b, x, y, d, and z are broadly described elsewhere herein. It should be apparent that this additive alloy is substantively different than second core alloy.
  • the GBM alloy does not contain any added boron.
  • the GBM alloy does not contain any added aluminum.
  • the GBM alloy does not contain any tin.
  • the GBM alloy does not contain any zinc.
  • any or all of these embodiments does not contain any added Al, B, Sn, or Zn may not necessarily preclude the possibility that these elements are present as unavoidable impurities, but the composition or GBE engineering does not rely on their presence for modifying the ultimately formed GBE magnets.
  • the first GBM alloy is substantially represented by the formula Nd j Dy k Co m Cu n Fe p , where j, k, m, n, and p, and their relationship with respect to one another are broadly described elsewhere herein.
  • the first GBM alloy comprises a material substantially represented by the formula Nd j Dy k Co m Cu n Fe p , where j, k, m, n, and p, and their relationship with respect to one another are broadly described elsewhere herein. That is, in these latter embodiments, the first GBM alloy contains one or more of the additional rare earth or transition metals as described herein, at levels also described herein.
  • the first GBM alloy may be amorphous (showing no features in an XRD pattern), semi-crystalline (showing only broadened features in an XRD pattern), or crystalline (showing well defined XRD features—see, e.g., FIG. 6 ).
  • crystalline in some embodiments, the form contains columnar and globulite crystals.
  • the first GBM alloy comprises a composition stoichiometry of AC b R x Co y Cu d M z
  • AC comprises Nd and Pr in an atomic ratio in a range of from 0:100 to 100:0 (with certain aspects of this range also including 0:100, 5:95, 10:90, 15:85, 20:80, 25:75, 30:70, 35:65, 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, 100:0), and b is a value in a range of from about 5 atom % to about 65 atom %.
  • the atomic ratio of Nd to Pr in AC is 100:0 (i.e., only Nd), 25:75, 50:50, 75:25, or 0:100 (i.e., only Pr).
  • Commercial sources of Nd and Pr are available for materials having these ratios, making them convenient sources for the manufacture of the GBM alloys.
  • b is a value in a range of from 5 to 10 atom %, 10 to 15 atom %, 15 to 20 atom %, 20 to 25 atom %, 25 to 30 atom %, 30 to 35 atom %, 35 to 40 atom %, 40 to 45 atom %, 45 to 50 atom %, 50 to 55 atom %, 55 to 60 atom %, 60 to 65 atom %, or any combination of two or more of these ranges.
  • One non-limiting exemplary combination range includes the range of from 10 to 50 atom %.
  • Other embodiments include those where the range is defined by integer values within these ranges, for example from about 9 to about 16 atom %.
  • R is one or more rare earth element.
  • the rare earth elements include members of the Lanthanide and Actinide series, though the members of the Lanthanide series are preferred. Members of this series include La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.
  • Various independent embodiments also include any one or more of these elements, though preferably containing at least 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 of these elements, more preferably at least 6, 7, 8, 9, 10, 11, 12, 13, or 14 of these elements.
  • R is Nd, Pr, La, Ce, Gd, Ho, Er, Yb, Dy, Tb, or a combination of 2, 3, 4, 5, 6, 7, or 8 of these separate elements, preferably at least 3, 4, 5, 6, 7, or 8 of these separate elements. It should be appreciated that in individual embodiments, any element or elements within the class of rare earth elements may be individually included in a sub-genus or individually excluded from the genus or sub-genus. Sm is specifically excluded in some of these combinations.
  • x is a value in a range of from about 5 atom % to about 75 atom %. In other independent embodiments, x is a value in a range of from 5 to 10 atom %, 10 to 15 atom %, 15 to 20 atom %, 20 to 25 atom %, 25 to 30 atom %, 30 to 35 atom %, 35 to 40 atom %, 40 to 45 atom %, 45 to 50 atom %, 50 to 55 atom %, 55 to 60 atom %, 60 to 65 atom %, 65 to 70 atom %, 70 to 75 atom %, or any combination of two or more of these ranges.
  • Exemplary, non-limiting, combination ranges include 30 to 60 atom % or 10 to 60 atom %. Other embodiments include those where the range is defined by integers within these ranges, for example from about 38 to about 48 atom %. Again, as described elsewhere, the disclosure described combinations of elements are separable and individual elements as combinable. As but one example of this, referring to R and x, in some embodiments, R comprises at least three or more different rare earth elements, the total (i.e., x) representing a value in a range described above, for example the range being from about 10 atom % to about 60 atom % of the first GBM alloy.
  • AC b R x Co y Cu d M z , Co is present in the first GBM alloy in an amount ranging from about 20 atom % to about 60 atom %.
  • y is a value in a range of from 20 to 25 atom %, 25 to 30 atom %, 30 to 35 atom %, 35 to 40 atom %, 40 to 45 atom %, 45 to 50 atom %, 50 to 55 atom %, 55 to 60 atom %, or any combination of two or more of these ranges; exemplary, non-limiting combination ranges include 30 to 40 atom %.
  • Other embodiments include those where the range is defined by integers within these ranges, for example from about 32 atom % to about 46 atom %.
  • AC b R x Co y Cu d M z , Cu is present in the first GBM alloy in a range of from about 0.01 atom % to 15 atom %.
  • d is a range of from 0.01 to 0.05 atom %, 0.05 to 0.1 atom %, 0.1 to 0.15 atom %, 0.15 to 0.2 atom %, 0.2 to 0.25 atom %, 0.25 to 0.5 atom %, 0.5 to 1 atom %, 1 to 1.5 atom %, 1.5 to 2 atom %, 2 to 2.5 atom %, 2.5 to 3 atom %, 3 to 3.5 atom %, 3.5 to 4 atom %, 4 to 4.5 atom %, 4.5 to 5 atom %, 5 to 5.5 atom %, 5.5 to 6 atom %, 6 to 7 atom %, 7 to 8 atom %, 8 to 9 atom %, 9 to 10 atom %, 10 to 11 atom
  • Cu is present in a range of from 0.01 to 6 atom %.
  • Other embodiments include those where the range is defined by one tenth integer values within these ranges, for example from about 3.1 to about 8.9 atom %.
  • AC b R x Co y Cu d M z , M is at least one transition metal element, exclusive of Cu and Co, and is present in the first GBM alloy in an amount ranging from about 0.01 atom % to about 18 atom %.
  • the presence of low levels of Zr in the presence of Fe appears to provide specific benefits described herein.
  • transition metals includes the elements of Groups 3 to 12 and Rows 4 to 6 of the periodic table, exclusive of Cu and Co, which are accounted for separately in the formula.
  • the transition metals include, for example, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Rh, Ir, Ni, Pd, Pt, Ag, Au, Zn, Cd, and Hg.
  • Various independent embodiments also include any one or more of these elements, though preferably containing at least 3, 4, 5, 6, 7, 8, 9, or 10 of these elements, more preferably at least 6, 7, 8, 9, or 10 of these elements.
  • M is Ag, Au, Fe, Ga, Mo, Nb, Ni, Ti, V, W, Y, Zr, or a combination of two or more of these elements.
  • M comprises Fe and Zr.
  • M comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13 separate transition metal elements, exclusive of Cu and Co, preferably at least 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 separate transition metal elements, exclusive of Cu and Co.
  • any element or elements within the class of transition metal elements may be individually included in a sub-genus or individually excluded from the genus or sub-genus.
  • this genus of transition metals does not include any of the Lanthanide or Actinide series of elements or Cu or Co, which are separately considered in the formula for the first GBM alloy.
  • M is present in the first GBM alloy in a range of from about 0.01 atom % to 10 atom %.
  • z is a range of from 0.01 to 0.05 atom %, 0.05 to 0.1 atom %, 0.1 to 0.15 atom %, 0.15 to 0.2 atom %, 0.2 to 0.25 atom %, 0.25 to 0.5 atom %, 0.5 to 1 atom %, 1 to 1.5 atom %, 1.5 to 2 atom %, 2 to 2.5 atom %, 2.5 to 3 atom %, 3 to 3.5 atom %, 3.5 to 4 atom %, 4 to 4.5 atom %, 4.5 to 5 atom %, 5 to 5.5 atom %, 5.5 to 6 atom %, 6 to 7 atom %, 7 to 8 atom %, 8 to 9 atom %, 9 to 10 .
  • M (and so the GBM alloy) does not contain any added aluminum.
  • M (and so the GBM alloy) does not contain any tin.
  • M (and so the GBM alloy) does not contain any zinc.
  • the circumstances in which any or all of these embodiments does not contain any added Al, B, Sn, or Zn may not necessarily preclude the possibility that these elements are present as unavoidable impurities, but the composition or GBE engineering does not rely on their presence for modifying the ultimately formed GBE magnets.
  • the amount of Fe contained in M is in a range of 0 to 0.5 atom %, from 0.5 to 1 atom %, from 1.5 to 2 atom %, from 2 to 2.5 atom %, from 2.5 to 3 atom %, for 3 to 3.5 atom %, from 3.5 to 4 atom %, from 4 to 4.5 atom %, from 4.5 to 5 atom %, from 5.5 to 6 atom %, from 6 to 6.5 atom %, from 6.5 to 7 atom %, from 7 to 7.5 atom %, from 7.5 to 8 atom %, or any combination of two or more of these ranges, for example from 0.5 to 4 atom %
  • the sum of b+x+y+d+z is greater than 95 atom %. In some preferred embodiments, this sum is greater than one or more of 98, 99, 99.5, 99.8, or 99.9 atom %, most preferably up to 99.9 atom % or practically 100 atom %. Any variance from 100 atom % reflects accidental impurities or deliberate additions of other elements, for example, main group elements of the periodic table, for example introduced during process or from the raw materials used in preparing the alloys. Such impurities may include Al, C, Si, N, O, P, for example. Typically, the first GBM alloy contains less than 0.1 weight % oxygen or carbon.
  • the first GBM alloy comprises at least neodymium, praseodymium, dysprosium, cobalt, copper, and iron.
  • Zr is also present.
  • nickel and/or cobalt are present in the first GBM alloy and, when present, can together account for at least 36 atom % of the total composition of the first GBM alloy.
  • iron and/or titanium are present in the first GBM alloy and, when present, can together account for at least 2 atom % of the total composition of the first GBM alloy.
  • the first GBM alloy is substantially represented by the formula of (Nd 0.01-0.18 Pr 0.01-0.18 Dy 0.3-0.5 Tb 0.3-0.5 ) aa (Co 0.85-0.95 Cu 0.04-0.15 Fe 0.01-0.08 ) bb (Zr 0.00-1.00 ) cc ; wherein:
  • aa is a value in a range of from 42 atom % to 75 atom %;
  • bb is a value in a range of from 6 atom % to 60 atom %.
  • cc is a value in a range of from 0.01 atom % to 18 atom %;
  • Nd+Pr is greater than 12 atom %
  • Nd+Pr+Dy+Tb is greater than at least one of 95, 98, 99, 99.5, 99.8, or 99.9 atom % to about 99.9 or 100 atom %;
  • Co+Cu+Fe is greater than 95, 98, 99, 99.5, 99.8, or 99.9 atom % to about 99.9 or 100 atom %;
  • aa+bb+cc is greater than 0.995 to about 0.999 or 1.
  • compositions are subsets, and incorporate the specific features, of the more general formula AC b R x Co y Cu d M z , as otherwise defined herein.
  • Nd and Pr are described in the context (i.e., of (Nd 0.01-0.18 Pr 0.01-0.18 Dy 0.3-0.5 Tb 0.3-0.5 ) aa ) as independently present in a range from 1 to 18 atom %.
  • these independent ranges may further be defined as from 1 to 2 atom %, from 2 to 3 atom %, from 3 to 4 atom %, from 4 to 5 atom %, from 5 to 6 atom %, from 6 to 7 atom %, from 7 to 8 atom %, from 8 to 9 atom %, from 9 to 10 atom %, from 10 to 11 atom %, from 11 to 12 atom %, from 12 to 13 atom %, from 13 to 14 atom %, from 14 to 15 atom %, from 15 to 16 atom %, from 16 to 17 atom %, from 17 to 18 atom %, or any combination of two or more of these ranges, for example, from 4 to 18 atom %.
  • Dy and Tb are described in the context (i.e., of (Nd 0.01-0.18 Pr 0.01-0.18 Dy 0.3-0.5 Tb 0.3-0.5 ) aa ) as independently present in a range from 30 to 50 atom %.
  • these independent ranges may further be defined as from 30 to 32 atom %, from 32 to 34 atom %, from 34 to 36 atom %, from 36 to 38 atom %, from 38 to 40 atom %, from 40 to 42 atom %, from 42 to 44 atom %, from 44 to 46 atom %, from 46 to 48 atom %, from 48 to 50 atom %, or any combination of two or more of these ranges, for example, from 36 to 42 atom %.
  • Co is described in the context (i.e., of (Co 0.85-0.95 Cu 0.04-0.15 Fe 0.00-0.08 ) bb ) as independently present in a range from 85 to 95 atom %.
  • these independent ranges may further be defined as from 85 to 85.5 atom %, from 85.5 to 86 atom %, from 86 to 86.5 atom %, from 86.5 to 87 atom %, from 87 to 87.5 atom %, from 87.5 to 88 atom %, from 88 to 88.5 atom %, from 88.5 to 89 atom %, from 89 to 89.5 atom %, from 89.5 to 90 atom %, from 90 to 90.5 atom %, from 90.5 to 91 atom %, from 91 to 91.5 atom %, from 91.5 to 92 atom %, from 92 to 92.5 atom %, from 92.5 to 93 atom %, from 93 to 94 atom %, from 90 to 9
  • Cu is described in the context (i.e., of (Co 0.85-0.95 Cu 0.04-0.15 Fe 0.00-0.05 ) bb ) as independently present in a range from 4 to 15 atom %.
  • these independent ranges may further be defined as from 4 to 4.5 atom %, from 4.5 to 5 atom %, from 5 to 5.5 atom %, from 5.5 to 6 atom %, from 6 to 6.5 atom %, from 6.5 to 7 atom %, from 7 to 7.5 atom %, from 7.5 to 8 atom %, from 8 to 8.5 atom %, from 9 to 9.5 atom %, from 9.5 to 10 atom %, from 10 to 10.5 atom %, from 10.5 to 11 atom %, from 11 to 11.5 atom %, from 11.5 to 12 atom %, from 12 to 12.5 atom %, from 12.5 to 13 atom %, from 13 to
  • Fe is described in the context (i.e., of (Co 0.85-0.95 Cu 0.04-0.15 Fe 0.00-0.08 ) bb ) as independently present in a range from 1 to 8 atom %.
  • these independent ranges may further be defined as from 1 to 1.5 atom %, from 1.5 to 2 atom %, from 2 to 2.5 atom %, from 2.5 to 3 atom %, from 3 to 3.5 atom %, from 3.5 to 4 atom %, from 4 to 4.5 atom %, from 4.5 to 5 atom %, from 5 to 5.5 atom %, from 5.5 to 6 atom %, from 6 to 6.5 atom %, from 6.5 to 7 atom %, from 7 to 7.5 atom %, from 7.5 to 8 atom %, or any combination of two or more of these ranges, for example, from 85 to 93 atom %.
  • Zr is described in the context (i.e., of (Zr 0.00-1.00 ) cc ) as independently present in a range from 0 to 100 atom %.
  • these independent ranges may further be defined as from 0 to 5 atom %, from 5 to 10 atom %, from 10 to 15 atom %, from 15 to 20 atom %, from 20 to 25 atom %, from 25 to 3 atom %, from 30 to 35 atom %, from 35 to 40 atom %, from 40 to 45 atom %, from 45 to 50 atom %, from 90 to 55 atom %, from 55 to 60 atom %, from 60 to 65 atom %, from 65 to 70 atom %, from 70 to 75 atom %, from 75 to 80 atom %, from 80 to 85 atom %, from 85 to 90 atom %, from 90 to 95 atom %, from 95 to 100 atom %, or any combination of two or more of these ranges
  • compositions may be described more specifically by a stoichiometric formula of (Nd 0.16 Pr 0.06 Dy 0.39 Tb 0.39 ) aa (Co 0.85 Cu 0.12 Fe 0.03 ) bb (Zr 1.00 ) cc .
  • Individual variances of any of the parenthetical values may independently be ⁇ 0.01, ⁇ 0.02, ⁇ 0.04, ⁇ 0.06 ⁇ 0.0.8, or ⁇ 0.1.
  • aa is a value in a range of from 42 to 44 atom %, 44 to 46 atom %, 46 to 48 atom %, 48 atom % to 50 atom %, 50 to 52 atom %, 52 to 54 atom %, 54 to 56 atom %, 56 to 58 atom %, 58 to 60 atom %, 60 to 62 atom %, 62 to 64 atom %, 64 to 68 atom %, 68 to 70 atom %, 70 to 72 atom %, 72 to 75 atom %, or any combination of two or more of these ranges, for example, from 52 to 56 atom %.
  • bb is a value in a range of from 6 to 8 atom %, from 8 to 10 atom %, from 10 to 12 atom %, from 12 to 14 atom %, from 14 to 16 atom %, from 16 to 18 atom %, from 18 to 20 atom %, from 20 to 22 atom %, from 22 to 24 atom %, from 24 to 26 atom %, from 26 to 28 atom %, from 28 to 30 atom %, from 30 to 32 atom %, from 32 to 34 atom %, from 34 to 16 atom %, from 36 to 38 atom %, from 38 to 40 atom %, from 40 to 42 atom %, from 42 to 44 atom %, from 44 to 46 atom %, from 46 to 48 atom %, from 48 to 50 atom %, from 50 to 52 atom %, from 52 to 54 atom %, from 54 to 56 atom %, from 56 to 58 atom %, from 58
  • cc is a value in a range of from 0.01 to 0.02 atom %, from 0.02 to 0.03 atom %, from 0.03 to 0.04 atom %, from 0.04 to 0.05 atom %, from 0.05 to 0.06 atom %, from 0.06 to 0.07 atom %, from 0.07 to 0.8 atom %, from 0.08 to 0.09 atom %, from 0.09 to 0.1 atom %, from 0.1 to 0.2 atom %, from 0.2 to 0.3 atom %, from 0.3 to 0.4 atom %, from 0.4 to 0.5 atom %, from 0.5 to 0.6 atom %, from 0.6 to 0.7 atom %, from 0.7 to 0.8 atom %, from 0.8 to 0.9 atom %, from 0.9 to 1 atom %, from 1 to 2 atom %, from 2 to 3 atom %, from 3 to 4 atom %, from 4 to 5 atom %, from 5 to 6
  • the alloy is represented by the stoichiometry of Nd 8.7 ⁇ 0.4 atom %; Pr 3.3 ⁇ 0.4 atom %; Dy 21.2 ⁇ 0.4 atom %; Tb 21.2 ⁇ 0.5 atom %; Co 38.2 ⁇ 0.5 atom %; Cu 5.4 ⁇ 0.4 atom %; Fe 1.3 ⁇ 0.3 atom %; Zr 0.6 ⁇ 0.5 atom %, which may be represented as Nd 0.9 Pr 0.3 Dy 0.21 Tb 0.22 Co 0.38 Cu 0.05 Fe 0.01 Zr 0.01 (which may alternatively be described as, corresponding to:
  • this material may be derived from virgin or recycled materials, and in either case may be doped may optionally doped with one or more dopants. Again, these descriptions apply to the second core alloy, whether with respect to the composition itself or its use in one or more methods.
  • the second core alloy is magnetic, paramagnetic, ferromagnetic, antiferromagnetic, superparamagnetic, or can be made so under appropriate conditions. Typically, they are made to exhibit such character in the final sintered bodies.
  • G is defined as comprising a rare earth element, where G is most broadly defined in terms of the rare earth elements, or combination of rare earth elements defined herein with respect to R.
  • G is defined in terms ofNd, Pr, La, Ce, Gd, Ho, Er, Yb, Dy, Tb, or a combination thereof.
  • G is substantially Nd with or without Pr.
  • G is substantially Nd.
  • the term “substantially Nd” refers to a composition in which the bulk of rare earth element content is Nd (e.g., greater than 95, 98, or 99 atom %, but may be doped with other rare earth elements).
  • the nature of the rare earth element(s) in this second core alloy may be the same or different as those in the first GBM alloy, with respect to specific chemical or stoichiometric or proportional basis, or combination thereof. Typically, the rare earth combinations in the first GBM and second core alloys are different.
  • the second core alloy may be further optionally doped with one or more transition metals or main group elements.
  • these dopants comprise one or more of Dy, Gd, Tb, Al, Co, Cu, Fe, Ga, Ti, or Zr.
  • the second core alloy is further optionally doped with up to 6.5 atom % Dy; up to 3 atom % Gd; up to 6.5 atom % Tb; up to 1.5 atom % Al, up to 4 atom % Co, up to 0.5 atom % Cu, up to 0.5 atom % Fe, up to 0.3 atom % Ga, up to 0.2 atom % Ti, up to 0.1 atom % Zr, or combination thereof.
  • the second core alloy may be doped with Dy in a range of from 0 to 0.5 atom %, from 0.5 to 1 atom %, from 1 to 1.5 atom %, from 1.5 to 2 atom %, from 2 to 2.5 atom %, from 2.5 to 3 atom %, from 3 to 3.5 atom %, from 3.5 to 4 atom %, from 4 to 4.5 atom %, from 4.5 to 5 atom %, from 5 to 5.5 atom %, from 5.5 to 6 atom %, from 6 to 6.5 atom %, or any combination of two or more of these ranges.
  • the second core alloy may be doped with Tb in a range of from 0 to 0.5 atom %, from 0.5 to 1 atom %, from 1 to 1.5 atom %, from 1.5 to 2 atom %, from 2 to 2.5 atom %, from 2.5 to 3 atom %, from 3 to 3.5 atom %, from 3.5 to 4 atom %, from 4 to 4.5 atom %, from 4.5 to 5 atom %, from 5 to 5.5 atom %, from 5.5 to 6 atom %, from 6 to 6.5 atom %, or any combination of two or more of these ranges.
  • the second core alloy may be doped with Gd in a range of from 0 to 0.5 atom %, from 0.5 to 1 atom %, from 1 to 1.5 atom %, from 1.5 to 2 atom %, from 2 to 2.5 atom %, from 2.5 to 3 atom %, or any combination of two or more of these ranges.
  • the second core alloy may be doped with Al in a range of from 0 to 0.5 atom %, from 0.5 to 1 atom %, from 1 to 1.5 atom %, or any combination of two or more of these ranges.
  • the second core alloy may be doped with Co in a range of from 0 to 0.5 atom %, from 0.5 to 1 atom %, from 1 to 1.5 atom %, from 1.5 to 2 atom %, from 2 to 2.5 atom %, from 2.5 to 3 atom %, from 3 to 3.5 atom %, from 3.5 to 4 atom %, or any combination of two or more of these ranges.
  • the second core alloy may be doped with Cu in a range of from 0 to 0.05 atom %, from 0.05 to 0.1 atom %, from 0.1 to 0.15 atom %, from 0.15 to 0.2 atom %, from 0.2 to 0.25 atom %, from 0.25 to 0.3 atom %, from 0.3 to 0.35 atom %, from 0.35 to 0.4 atom %, from 0.4 to 0.45 atom %, from 0.45 to 0.5 atom %, or any combination of two or more of these ranges.
  • the second core alloy may be doped with Fe in a range of from 0 to 0.05 atom %, from 0.05 to 0.1 atom %, from 0.1 to 0.15 atom %, from 0.15 to 0.2 atom %, from 0.2 to 0.25 atom %, from 0.25 to 0.3 atom %, from 0.3 to 0.35 atom %, from 0.35 to 0.4 atom %, from 0.4 to 0.45 atom %, from 0.45 to 0.5 atom %, or any combination of two or more of these ranges.
  • the second core alloy may be doped with Ga in a range of from 0 to 0.05 atom %, from 0.05 to 0.1 atom %, from 0.1 to 0.15 atom %, from 0.15 to 0.2 atom %, from 0.2 to 0.25 atom %, from 0.25 to 0.3 atom %, or any combination of two or more of these ranges.
  • the second core alloy may be doped with Ti in a range of from 0 to 0.01 atom %, from 0.01 to 0.02 atom %, from 0.02 to 0.03 atom %, from 0.03 to 0.04 atom %, from 0.04 to 0.05 atom %, from 0.05 to 0.06 atom %, from 0.06 to 0.07 atom %, from 0.07 to 0.08 atom %, from 0.04 to 0.09 atom %, from 0.09 to 0.1 atom %, from 0.1 to 0.11 atom %, from 0.11 to 0.12 atom %, from 0.12 to 0.13 atom %, from 0.13 to 0.14 atom %, from 0.14 to 0.15 atom %, from 0.15 to 0.16 atom %, from 0.16 to 0.17 atom %, from 0.17 to 0.18 atom %, from 0.18 to 0.19 atom %, from 0.19 to 0.2 atom %, or any combination of two or more of these ranges.
  • the second core alloy may be doped with Zr in a range of from 0 to 0.005 atom %, from 0.005 to 0.01 atom %, from 0.01 to 0.015 atom %, from 0.015 to 0.02 atom %, from 0.02 to 0.025 atom %, from 0.025 to 0.03 atom %, from 0.03 to 0.035 atom %, from 0.035 to 0.04 atom %, from 0.04 to 0.045 atom %, from 0.045 to 0.05 atom %, from 0.05 to 0.055 atom %, from 0.055 to 0.06 atom %, from 0.06 to 0.065 atom %, from 0.065 to 0.07 atom %, from 0.07 to 0.075 atom %, from 0.075 to 0.08 atom %, from 0.08 to 0.085 atom %, from 0.085 to 0.09 atom %, from 0.09 to 0.095 atom %, from 0.095 to 0.
  • the mixed alloy particles are processed further by (c) compressing the population of mixed alloy particles together to form a green body, under a magnetic field of a suitable strength to align the magnetic particles with a common direction of magnetization in an inert atmosphere.
  • These particles may have designed shapes to facilitate packing of particles within a compact. Shapes include spherical, angular, dendritic, and disc-shaped. A blend of different shaped powder particles may help improve packing efficiency of the mixed alloy powder in the compact.
  • the resulting green body provides a solid body comprising an intimate mixture of the mixed alloy particles.
  • the mixed alloy particles may be compressed into any predetermined shape suitable for the intended use of the final sintered body.
  • the mixed alloy particles are compressed in dry form; in other embodiments, a suitable lubricant may be used. Suitable lubricants may comprise fatty acid esters or amides or polyglycols, for example, but must be chosen such that when the green bodies are sintered, there is no or acceptable levels of C, N, or O residues left in the sintered bodies. Such levels of C, N, and/or O are typically individually less than 5000 ppm, 2500 ppm, 1000 ppm, less than 100 ppm, or less than 10 ppm by weight.
  • inert atmosphere refers to an atmosphere or environment that is substantially absent of oxygen, water, or other oxidizing agents. “Substantially absent” refers either to the absence of deliberately added oxygen, water, or other oxidizing agent, and preferably where best efforts are taken to exclude these materials. Dry nitrogen or argon atmospheres are typically suitable for this purpose.
  • the compressing is typically done under a compressive force in a range of from about 800 to about 3000 kN, though the methods are not necessarily limited to these force levels, provided the applied forces provide the densities deemed desirable for the final processing and product.
  • the force is applied on one or more applications, with each application comprising application of a force in a range of 800 to 1000 kN, from 1000 to 1500 kN, from 1500 to 2000 kN, from 2000 to 2500 kN, from 2500 to 3000 kN, or any combination thereof.
  • the compression is done with the application of a force in a range of from about 1000 kN to about 2500 kN.
  • the materials are subjected to a magnetic field in a range of from about 0.2 T to about 2.5 T (160 to 2000 A/m), or sufficient to align the magnetic particles with a common direction of magnetization.
  • the magnetic field is applied in at least one range of from 0.2 to 0.5 T, from 0.5 to 1 T, from 1 to 1.5 T, from 1.5 to 2 T, from 2 to 2.5 T, or any combination of two or more of these ranges.
  • the present methods further comprise (d) heating the green body to at least one temperature in a range of from about 800° C. to about 1500° C. for a time sufficient to sinter the green body into a sintered body.
  • the ranges for such sintering include those from 800° C. to 850° C., from 850° C. to 900° C., from 900° C. to 950° C., from 950° C. to 1000° C., from 1000° C. to 1050° C., from 1050° C. to 1100° C., from 1100° C. to 1150° C., from 1150° C. to 1200° C., from 1200° C. to 1250° C., from 1250° C.
  • the specific sintering conditions depend on the chemical nature and physical form of the particles in the green body (e.g., chemical compositions and particle size), in some embodiments, certain of these compositions can be sintered at temperatures from about 1050 to about 1085° C. for about 1 to 5 hours; typically about 1080° C. for 3.5 hours. In some embodiments, the sintering process is carried out under combination of cycling vacuum and inert gas (e.g., argon) pressure while sintering occurs.
  • inert gas e.g., argon
  • the sintered bodies may be further (e) heat treated, so as to anneal, the sintered body in an environment of cycling vacuum and inert gas at a temperature in the range of from about 450° C. to about 600° C.
  • the sintered or sintering bodies are magnetized by (f) applying a magnetic field of sufficient strength to achieve final remanence and coercivity as described herein, for example, using a magnetic field in a range of from about 400 kA/m to about 1200 kA/m (0.5 to 1.5 T).
  • a magnetic field in a range of from about 400 kA/m to about 1200 kA/m (0.5 to 1.5 T).
  • a magnetic field may be applied during the sintering, after the sintering during annealing, after annealing, or during any two or more of these times.
  • the structure of the sintered bodies may be described in terms of sintered core shell particles, or grains, held together by a grain boundary composition.
  • Each of these core shell grains may be described in terms of a core, comprising the composition of the second core alloy, surrounded by multiple shells, the shells comprising intermediate alloy compositions formed from the diffusion of the R, Cu, Co, and M elements of the first GBM alloy into the matrix of the second core alloy particles.
  • the grain boundary composition then, reflects the composition of the first GBM alloy, less any portion of the elements that have migrated from the grain boundaries into the core shell particles or grains.
  • Such a composition may be seen as forming during the sintering of the unique mixed alloy particles, each of which may be envisioned as comprising a second core alloy “coated” by particles of the first GBM alloy, or during the subsequent ageing/annealing steps of the sintered body. While not intending to be necessarily bound by the correctness of any particular theory, one may envision that, initially, the lower melting GBM alloy distributes itself, substantially homogeneously, around and between the grains of the second core alloy particles. As heating continues, the mobile diffusible elements of the first GBM alloy migrate into the matrices of the second alloy core particles. As such, grain boundaries, especially triple junction grain boundaries, act as depots for the source of the migration of the elements of the first alloy into the second core alloy particles.
  • the grain boundaries tend to reflect the original composition of the first GBM alloy. That is, while the overall composition may be defined in terms of the composition and proportion of the original ingredients, subject to the presence of oxygen, carbon, and nitrogen additives which add or deplete during processing, the placement of these ingredients is subject to change during sintering, by virtue of their migration from the grain boundaries to the grains (and vice versa).
  • the phrase “grain boundaries tend to reflect the original composition of the first GBM alloy” is intended to connote this compositional change attributable to the migration of the elements of the grain boundary into the grains.
  • some of the transition metal elements appear both in the shells of the grains and the grain boundary compositions. Or some rare earth elements may occur in the shell(s) and in the grain boundary but not in the grain core. Since the grain boundaries (especially the triple junction grain boundaries) appear to act depots for the migrating or diffusing elements, in these embodiments, the concentration of the migrating or diffusing elements are higher in the grain boundary compositions than in the grains themselves. These concentration differences provide the chemical gradients that force the migration of the elements into the grains. For example, in some embodiments, since the sintered grains and the grain boundary alloys both contain cobalt and copper, the grain boundary is enriched in these elements, relative to their presence in the sintered particles.
  • the grain boundary alloy comprises cobalt and copper in combined amount of at least 20 weight %, relative to the total composition of the alloy, as measured by EDS and at least three rare earth elements and one transitional element, each not exceeding 10 weight % of the total alloy composition.
  • the size of the grain core may depend on the thermal history of the particles or sintered bodies, including the processing of the particles, the sintering, and subsequent annealing steps). Assuming the shells are formed from the inward migration or diffusion of the elements of the first GBM alloy, one would expect that only the central portion of the original second core alloy particle would retain its original compositional character, and that the size of the resulting core would depend on the thermal history of that particle. This core is expected to become smaller with prolonged heat treatment and higher temperatures of such treatment, for a given composition of the grain boundary composition, as more materials migrated inward. The improvements in magnetic performance (see Examples) are consistent with the formation of smaller sized cores of the second core alloy.
  • Nd 2 Fe 14 B e.g., 300 nm
  • larger grains e.g., >5 microns.
  • the challenge has been to provide sintered bodies comprising these smaller grains without their forming larger particles during sintering.
  • the present methods appear to provide a means for controllably achieving these smaller G 2 Fe 14 B grains, the grains being separated by the prescribed shells.
  • the sintered bodies comprise grains having a core of the second core alloy having dimensions in a range of from about 0.3 to about 3.9 microns.
  • the grain core may have at least one dimension in a range of from 0.3 to 0.4 microns, from 0.4 to 0.5 microns, from 0.5 to 0.6 microns, from 0.7 to 0.8 microns, from 0.8 to 0.9 microns, from 0.9 to 1 micron, from 1 to 1.1 microns, from 1.1 to 1.2 microns, from 1.2 to 1.3 microns, from 1.3 to 1.4 microns, from 0.4 to 0.5 microns, from 1.5 to 1.6 microns, from 1.7 to 0.8 microns, from 1.8 to 1.9 microns, from 1.9 to 2 microns, from 2 to 2.1 microns, from 2.1 to 2.2 microns, from 2.2 to 2.3 microns, from 2.3 to 2.4 microns, from 2.4 to 2.5 microns, from 2.5 to 2.6 microns, from 2.6 to 2.7 microns, from 2.7 to 2.8 microns, from 2.8 to 2.9 microns, from 2.9 to
  • the thickness of the shells may be less important than the size of the cores, but in some embodiments, the cumulative thickness of the shells is in a range of from about one to three microns, but in some embodiments, the cumulative thickness of the shells is in a range of from about 0.5 to 1, 1 to 1.5, 1.5 to 2.2 to 2.5, 2.5 to 3, 3 to 3.5, 3.5 to 4, 4 to 4.5, 4.5 to 5, or a range defined by any two or more of these ranges.
  • these core dimensions may reflect the diameter of a spherical or quasi-spherical core.
  • optimal sizes are those having at least one axis dimension in this range. It may also be convenient to describe the core in terms of proportionality with respect to the shell(s). In some embodiments, the relative proportion of the core dimension to the shell thickness is in a range of from about 1:10 to about 4:1.
  • the relative proportion of the core dimension to the shell thickness is in a range of from about 1:10 to about 1:8, from 1.8 to about 1:1.6, from about 1:6 to about 1:4, from about 1:4 to about 1:2, from about 1:2 to about 1:1, from about 1:1 to about 2:1, from about 2:1 to about 3:1, from about 3:1 to about 4:1, or a range defined by two or more of these ranges.
  • the shell structure and diffusion of heavy rare earths and other elements into each magnetic grains allows for their presence over the entire body of any magnet made with this material, so that high coercivity magnets can be made using minimal Dy, Tb, or other rare earth element, without any limitation of thickness or geometry (see, e.g., Example 3, Table 13).
  • the sintered body results from the sintering of chemically homogeneous or substantially homogeneous (as practically possible by solids mixing) mixed alloy particles, the composition of any body so produced (sintered core shell particles and grain boundaries) is substantially constant (for example, with a magnetic property varying by less than 10%, 5%, 4%, 3%, 2%, or 1%) throughout the body.
  • the term “substantially constant” refers to the practical absence of composition gradients through the body that would otherwise result from adding additives to one or more surfaces of a previously sintered body.
  • the variances in these gradients are described elsewhere herein. This feature de-limits the size and shapes of the homogeneous magnets so produced, as compared with those magnets produced by other means. That is, the substantial homogeneity of any magnetic material so produced is no longer limited to the diffusion of grain boundary additive to pre-sintered bodies.
  • Introducing Cu at the levels claimed for the GBM additive is believed to result in the formation of copper-rich aggregates within the boundary between the triple pocket junction (grain boundary phase) and G 2 Fe 14 B/Nd 2 Fe 14 B matrix grain at levels sufficient to provide one or both of (i) an increase in the surface energy between the G 2 Fe 14 B/Nd 2 Fe 14 B matrix grain and grain boundary grains and (ii) the formation of a thin layer which inhibits the diffusivity of Dy and Tb into the Nd 2 Fe 14 B matrix grains.
  • Additions of Cu is believed to help to resist embittlement of the final core shell sintered NdFeB product as well as increasing corrosion resistance by forming various copper-rare earth metal oxides.
  • introducing Co at the levels claimed for the GBM additive is believed to lead to the formation of a rare earth-cobalt oxide phase or phases, which may help inhibit the corrosion properties, such that the core shell sintered NdFeB (G 2 Fe 14 B phase) has increased corrosion resistance in the grain boundary phase as well as giving rise to core multi shell structure.
  • the presence of Zr in the GBM alloy is believed to result in an association with any iron also present in the composition, as introduced either in the first or second alloys. If localized in the grain boundaries or outer shells, the associated Zr—Fe alloys may be useful in preventing the propagation of the reverse domains during the demagnetization. The presence of Zr is believed also to induce the ferromagnetic coupling between the grain boundary and the matrix G 2 Fe 14 B phase by varying electron concentration in any such associated Fe—Zn structures. The introduction of Zr on the grain boundary may also help to increase the resistivity in the final core shell sintered NdFeB product.
  • the addition of various rare earth component (Nd, Pr, Dy, Tb) via the GBM additive is believed to also result in the formation of a rare earth rich shell or shells allowing for a reinforcing of magneto crystalline anisotropy around the core.
  • Each of the elements in the GBM additive is expected to have a different diffusivity into the core material.
  • the collective presence of these materials, Nd, Pr, Dy, Tb, Cu, Co, Zr, Fe, in the amounts claimed appear to provide an optimal balance of kinetic and thermodynamic properties for modulating the diffusion of these and other species into the bulk of the grain.
  • the diffusion of these materials into the G 2 Fe 14 B core may be modeled as an exponentially decaying periodic trend such as (Co*exp( ⁇ x/L)*sin(x/l+c)) where: C 0 is the initial concentration of each element at the grain boundary, L is the decay length and l is the diffusion wavelength, under the processing conditions.
  • GBE magnets are attractive not only because they can be prepared using much lower levels of rare earth elements such as Dy, Tb, Er, than with other methods to achieve similar properties, but because the resulting magnets exhibit comparable or superior properties, even in the face of these reduced Dy levels (see Tables 11-13). Compositions exhibiting such improved properties are also included in the scope of the disclosure. As shown in FIG. 4 , such magnets can exhibit increased coercivity (up to 90%), with a minimal loss of remanence. Such materials also exhibit enhanced corrosion resistance, and greater alpha and beta factors, representing a greater resistance to demagnetization.
  • GBE magnets described herein provide significant improvements in the reversible coefficients alpha (describing remanence) and beta (describing coercivity), particularly in the case where Dy Tb Co, Cu, Fe, Zr. GBE magnets exhibiting such improved properties are also included in the scope of the present invention.
  • GBE compositions having cores comprising doped or undoped G 2 Fe 14 B (including nominal Nd 2 Fe 14 B, dopant levels described elsewhere herein), comprising heavy rare earth elements (i.e., Dy, Tb, Ho, Er, Tm, Yb, or Lu, but especially Dy) at levels in a range of from 0.2 to 0.3 wt %, from 0.3 to 0.4 wt %, from 0.4 to 0.5 wt %, from 0.5 to 0.6 wt %, from 0.6 to 0.7 wt %, from 0.7 to 0.8 wt %, from 0.8 to 0.9 wt %, from 0.9 to 1.0 wt %, from 1.0 to 1.1 wt %, from 1.1 to 1.2 wt %, from 1.2 to 1.3 wt %, from 1.3 to 1.4 wt %, from 1.4 to 1.5 wt %, from 1.5 to 1.6 wt %
  • the specific attributes characterizing the sintered body particularly in the case of compositions specifically directed as having Nd 2 Fe 14 B cores, include:
  • this disclosure includes descriptions of the alloys, alloy and mixed-alloy particles, populations of alloy particles, green bodies, sintered bodies and their associated grains and grain boundaries and methods of these articles. Any description attributable to a method is also attributable to the article, and vice versa.
  • additional embodiments include those devices incorporating these magnets, such devices intended for use at temperatures in a range of from 80° C. to 200° C.
  • Such devices include head actuators for computer or tablet hard disks, erase heads, magnetic resonance imaging (MRI) equipment, magnetic locks, magnetic fasteners, loudspeakers, headphones or ear pods, mobile telephones and other consumer electronics (e.g., i-pods, electronic watches, ear pods, DVD and blue-ray players, CD and record players, microphones, home appliances), magnetic bearings and couplings, NMR spectrometers, linear and A/C motors, electric motors (for example, as used in cordless tools, servomotors, compression motors, synchronous, spindle and stepper motors, electric and power steering, drive motors for hybrid and electric vehicles), and electric generators (including wind turbines).
  • MRI magnetic resonance imaging
  • MRI magnetic resonance imaging
  • magnetic locks magnetic fasteners
  • loudspeakers loudspeakers
  • headphones or ear pods mobile telephones and
  • the present disclosure also contemplates the systems for making these materials. Again, many of the descriptions provided for the methods of making these core-shell materials are applicable to the description of the systems, and to the extent appropriate, these descriptions are incorporated here.
  • an apparatus comprising:
  • system comprising such an apparatus may be useful in executing the methods described herein, wherein the system further comprises one or more of:
  • a rotatable hydrogen reactor capable of treating solid magnetic materials with hydrogen at pressures in a range of from 1 to 10 bar (or, in some embodiments, higher, e.g., to 150 bar);
  • a compression device capable of applying a force in a range of from about 800 to about 3000 kN to a population of particles, the compression device fitted with a source of a magnetic field, the magnetic field source able to provide a magnetic field in a range of from about 0.2 T to about 2.5 T, while the compression device is applying the force to the population of particles;
  • a sintering chamber configured to provide alternative vacuum and inert atmosphere environments within the chamber while providing an internal temperature to the chamber in a range of from ambient to about 400° C., and further to about 1200° C.
  • such systems comprise two, three, four, or five of these aspects (a) through (e).
  • a method of preparing a sintered magnetic body having improved coercivity and remanence comprising:
  • a method of preparing a sintered magnetic body having improved coercivity and remanence comprising:
  • j is atomic percent in a range from 1 to 2, 2 to 3, 3 to 4, 4 to 5, 5 to 6, 6 to 7, 7 to 8, 8 to 9, 9 to 10, 10 to 11, 11 to 12, 12 to 13, 13 to 14, 14 to 15, 15 to 16, 16 to 17, 17 to 18, 18 to 19, 19 to 20 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • k is atomic percent in a range from 1 to 5, 5 to 10, 10 to 15, 15 to 20, 20 to 25, 25 to 30, 30 to 35, 35 to 40, 40 to 45, 45 to 50, 50 to 55, 55 to 60 20 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • m is atomic percent in a range from 1 to 5, 5 to 10, 10 to 15, 15 to 20, 20 to 25, 25 to 30, 30 to 35, 35 to 40, 40 to 45, 45 to 50, 50 to 55, 55 to 60 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • n is atomic percent in a range from 0.1 to 0.5, 0.5 to 1, 1 to 1.5, 1.5 to 2, 2 to 2.5, 2.5 to 3, 3 to 3.5, 3.5 to 4, 4 to 4.5, 4.5 to 5, 5 to 5.5, 5.5 to 6, 6 to 6.5, 6.5 to 7, 7 to 7.5, 7.5 to 8, 8.5 to 9, 9 to 9.5, 9.5 to 10, 10 to 12, 12 to 14, 14 to 16, 16 to 18, 18 to 20 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • p is atomic percent in a range from 1 to 2, 2 to 3, 3 to 4, 4 to 5, 5 to 6, 6 to 7, 7 to 8, 8 to 9, 9 to 10, 10 to 11, 11 to 12, 12 to 13, 13 to 14, 14 to 15, 15 to 16, 16 to 17, 17 to 18, 18 to 19, 19 to 20 atom % or a range comprising two or more of these ranges, relative to the entire composition;
  • j, k, m, n, and p are independently variable within their stated ranges provided that the sum ofj+k+m+n+p is greater than 95, 96, 97, 98, 99, 99.5, 99.8, or 99.9 atom % to about 99.9 atom % or 100 atom %.
  • Embodiment 1 or 2 wherein the homogenizing step (a) is preceded by treating coarse particles of either the first GBM or second core alloy or both the first GBM and second core alloys in the presence of hydrogen under conditions and for a time to allow absorption of the hydrogen into either the first GBM or second core alloy or both the first GBM and second core alloys.
  • Embodiments 1 or 4 to 6 as applied to Embodiment 1, wherein AC is present in a range of from about 5 atom % to about 15 atom % of the first GBM alloy.
  • b is a range of from 5 to 10 atom %, 10 to 15 atom %, 15 to 20 atom %, 20 to 25 atom %, 25 to 30 atom %, 30 to 35 atom %, 35 to 40 atom %, 40 to 45 atom %, 45 to 50 atom %, 50 to 55 atom %, 55 to 60 atom %, 60 to 65 atom %, or any combination of two or more of these ranges.
  • R is Nd, Pr, La, Ce, Gd, Ho, Er, Yb, Dy, Tb, or a combination thereof, preferably Dy and/or Tb.
  • R may comprise 1, 2, 3, 4, 5, 6, 7, or 8 separate rare earth elements, preferably at least 3, 4, 5, 6, 7, or 8 different rare earth elements.
  • x is a range of from 5 to 10 atom %, 10 to 15 atom %, 15 to 20 atom %, 20 to 25 atom %, 25 to 30 atom %, 30 to 35 atom %, 35 to 40 atom %, 40 to 45 atom %, 45 to 50 atom %, 50 to 55 atom %, 55 to 60 atom %, 60 to 65 atom %, 65 to 70 atom %, 70 to 75 atom % or any combination of two or more of these ranges; exemplary, non-limiting, combination ranges include 30 to 60 atom % or 10 to 60 atom %.
  • Embodiments 1 or 4 to 10 The method of any one of Embodiments 1 or 4 to 10, as applied to Embodiment 1, wherein Co is present in the first GBM alloy in a range of from about 35 atom % to 45 atom %.
  • y is a range of from 20 to 25 atom %, 25 to 30 atom %, 30 to 35 atom %, 35 to 40 atom %, 40 to 45 atom %, 45 to 50 atom %, 50 to 55 atom %, 55 to 60 atom %, or any combination of two or more of these ranges; exemplary, non-limiting combination ranges include 30 to 40 atom %.
  • d is a range of from 0.01 to 0.05 atom %, 0.05 to 0.1 atom %, 0.1 to 0.15 atom %, 0.15 to 0.2 atom %, 0.2 to 0.25 atom %, 0.25 to 0.5 atom %, 0.5 to 1 atom %, 1 to 1.5 atom %, 1.5 to 2 atom %, 2 to 2.5 atom %, 2.5 to 3 atom %, 3 to 3.5 atom %, 3.5 to 4 atom %, 4 to 4.5 atom %, 4.5 to 5 atom %, 5 to 5.5 atom %, 5.5 to 6 atom %, 6 to 7 atom %, 7 to 8 atom %, 8 to 9 atom %, 9 to 10 atom %,
  • M is Ag, Au, Co, Fe, Ga, Mo, Nb, Ni, Ti, V, W, Y, Zr, or a combination thereof.
  • M may comprise 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13 separate transition metal elements, exclusive of Cu and Co, preferably at least 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 separate transition metal elements, again exclusive of Cu and Co.
  • z is a range of from 0.01 to 0.05 atom %, 0.05 to 0.1 atom %, 0.1 to 0.15 atom %, 0.15 to 0.2 atom %, 0.2 to 0.25 atom %, 0.25 to 0.5 atom %, 0.5 to 1 atom %, 1 to 1.5 atom %, 1.5 to 2 atom %, 2 to 2.5 atom %, 2.5 to 3 atom %, 3 to 3.5 atom %, 3.5 to 4 atom %, 4 to 4.5 atom %, 4.5 to 5 atom %, 5 to 5.5 atom %, 5.5 to 6 atom %, 6 to 7 atom %, 7 to 8 atom %, 8 to 9 atom %, 9 to 10 atom %, 10 to
  • first GBM alloy comprises of at least neodymium, praseodymium, dysprosium, cobalt, copper, and iron.
  • Embodiment 26 wherein the compressing is done under a force in a range of from about 800 to about 3000 kN, preferably from about 1000 kN to about 2500 kN.
  • Embodiment 29 further comprising (e) heat treating (annealing) the sintered body in an environment of cycling vacuum and inert gas at a temperature in the range of from about 450° C. to about 600° C.
  • Embodiments 29 or 30, further comprising (f) applying a magnetic field to the sintering or sintered body of sufficient strength to achieve final remanence and coercivity as described herein, for example, using a magnetic field in a range of from about 400 kA/m to about 1200 kA/m (0.5 to 1.5 T).
  • the sintered particles comprise a core of the second core alloy having a dimension in a range of from about 0.3 to about 2.9 microns.
  • the sintered core shell particles comprise quasi-concentric shells surrounding the core, these shells compositionally defined by shell layers of Co, Cu, and M elements within a matrix of the second core alloy.
  • the relative proportion of the core diameter to the shell thickness is in a range of from about 1:25 to about 4:1. In other embodiments, the relative proportion of the core diameter to the shell thickness is in a range of from about 1:10 to about 4:1.
  • the grain boundary alloy comprises cobalt and copper in combined amount of at least 20 wt %, relative to the total composition of the alloy, as measured by EDS and at least three rare earth elements and one transitional element, each not exceeding 10 wt % of the total alloy composition.
  • Embodiments 1 to 36 where the overall chemical composition within a particle or within a grain boundary are identified using Energy dispersive X-ray Spectroscopy (EDS) mapping across a fractured or polished surface.
  • EDS Energy dispersive X-ray Spectroscopy
  • the particle or population of particles is defined in terms of the compositions associated with the methods of preparing, but is not necessarily prepared by these methods.
  • a green body prepared by a method of any one of Embodiments 26 to 28 or 36 to 37 is defined in terms of the compositions associated with the methods of preparing, but is not necessarily prepared by these methods.
  • a sintered body prepared by a method of any one of Embodiments 29 to 37 Such a sintered body may be characterized by its overall structure, including chemical composition and distribution within its grains and grain boundaries and the enhanced performance, relative to structures not having these features.
  • the green body is defined in terms of the compositions associated with the methods of preparing, but is not necessarily prepared by these methods.
  • a device comprising a sintered magnetized body of Embodiment 31, the device selected from a group consisting of head actuators for computer or tablet hard disks, erase heads, magnetic resonance imaging (MRI) equipment, magnetic locks, magnetic fasteners, loudspeakers, headphones or ear pods, mobile telephones and other consumer electronics (such as i-pods, electronic watches, ear pods, DVD and blue-ray players, CD and record players, microphones, home appliances), magnetic bearings and couplings, NMR spectrometers, electric motors (for example, as used in cordless tools, servomotors, compression motors, synchronous, spindle and stepper motors, electric and power steering, drive motors for hybrid and electric vehicles), and electric generators (including wind turbines).
  • the sintered magnetized body is defined in terms of the compositions associated with the methods of preparing, but is not necessarily prepared by these methods.
  • a composition comprising an alloy is represented by the formula: AC b R x Co y Cu d M z , wherein:
  • (A) AC comprises Nd and Pr in an atomic ratio in a range of from 0:100 to 100:0, and b is a value in a range of from about 5 atom % to about 65 atom %;
  • R is one or more rare earth element and x is a value in a range of from about 5 atom % to about 75 atom %;
  • (D) y is a value in a range of from about 20 atom % to about 60 atom %;
  • (E) d is a value in a range of from about 0.01 atom % to about 12 atom %;
  • (F) M is at least one transition metal element, exclusive of Cu and Co, and z is a value in a range of from about 0.01 to about 18 atom %;
  • (G) b+x+y+d+z is greater than one or more of 95, 98, 99, 99.5, 99.8, or 99.9 atom % to about 99.9 atom % or 100 atom %;
  • the composition contains less than 0.1 wt % oxygen or carbon.
  • the alloy is present as a population of particles having a mean particle diameter in a range of from 0.5 microns to about 5 microns, or any individual or combination of sub-ranges including from 0.5 to 0.8 microns, from 0.8 to 1 micron, from 1 to 2 microns, from 2 to 2.5 microns, from 2.5 to 3 microns, from 3 to 4 microns, or from 4 to 5 microns, or a range combining two or more of these ranges, for example 1 micron to 4 microns.
  • composition of Embodiment 42 wherein the atomic ratio of Nd to Pr in AC is 100:0, 25:75, 50:50, 75:25, or 0:100, or any ratio therebetween.
  • Embodiment 42 or 43 wherein R is La, Ce, Gd, Ho, Er, Yb, Dy, Tb, or a combination of two or more of these elements.
  • R is a combination of 2, 3, 4, 5, or 6 of La, Ce, Gd, Ho, Er, Yb, Dy, or Tb.
  • M is Ag, Au, Co, Fe, Ga, Mo, Nb, Ni, Ti, V, W, Y, Zr, or a combination thereof.
  • M is y a combination of 2, 3, 4, 5, or 6 of Ag, Au, Co, Fe, Ga, Mo, Nb, Ni, Ti, V, W, Y, or Zr.
  • aa is a value in a range of from 42 atom % to 75 atom %;
  • bb is a value in a range of from 6 atom % to 60 atom %.
  • cc is a value in a range of from 0.01 atom % to 18 atom %;
  • Nd+Pr is greater than 12 atom %
  • Nd+Pr+Dy+Tb are greater than one or more of 95, 98, 99, 99.5, 99.8, or 99.9 atom % to about 99.9 or 100 atom %;
  • Individual variances of any of the parenthetical values may independently be ⁇ 0.01, ⁇ 0.02, ⁇ 0.04, ⁇ 0.06 ⁇ 0.0.8, or ⁇ 0.1.
  • composition of any one of Embodiments 42 to 48 the composition being in a form containing columnar and globulite crystals.
  • composition of any one of Embodiments 42 to 49 the composition being in an amorphous form.
  • An apparatus for mixing magnetic particles comprising:
  • a system comprising the apparatus of Embodiment 52, the system further comprising one or more of:
  • a rotatable outgassing chamber capable of being evacuated and heated to at least partially outgas the hydrogen-containing magnetic materials
  • a compression device capable of applying a force in a range of from about 800 to about 3000 kN to a population of particles, the compression device fitted with a source for applying a magnetic field, the magnetic field source able to provide a magnetic field in a range of from about 0.2 T to about 2.5 T, while the compression device is applying the force to the population of particles;
  • a sintering chamber configured to provide alternative vacuum and inert atmosphere environments within the chamber while providing an internal temperature to the chamber in a range of from about 400° C. to 1200° C.
  • the sintering chamber is fitted with a source for applying a magnetic field.
  • the system comprises 2, 3, 4, or 5 of the elements (a) to (e).
  • GBE-NdFeB magnets and other magnets described herein can be produced as follows.
  • the first GBM alloy is based upon the formula AC b R x Co y Cu d M z , and can be produced by a number of techniques described herein.
  • FIG. 3 shows a schematic representation of various embodiments of the processes described here.
  • large bulk pieces of the GBM alloy were prepared by melting together elements at 1500° C. and pouring the liquid metal into a book mold. Such a casting system is then used to produce a book or cylinder (diameter of 60 mm and length of 200 mm) mold.
  • the cooling speed can vary from 1200° C./min to 1400° C./min.
  • GBM alloys were also prepared as continuous alloy droplets by solidifying at cooling rates, of about 550° C./sec in jet of inert gas under a 0.2 T magnetic field from melted metals.
  • GBM alloy can also be strip cast into flakes with dimensions of 5 cm ⁇ 5 cm ⁇ 7 cm.
  • the GBM alloy has also been introduced to strip cast flakes corresponding to a composition of a hard magnetic material in a number of ways, described herein.
  • strip-cast NdFeB-type flake (with dimensions of 0.2 cm ⁇ 2-6 cm ⁇ 2-8 cm, the strip casting providing demagnetized NdFeB-type flake) and GBM alloy (with dimensions of 5 cm ⁇ 5 cm ⁇ 7 cm) were partially mixed together with different weight additions, ranging from about 0.1 to about 6.5 weight % in a hydrogen mixing chamber, though the relative proportions of the two alloys is not limited to this value).
  • the thickness distribution of the strip cast flakes was Gaussian with a +/ ⁇ 2.5% standard deviation tolerated around the mean value.
  • the GBM flake initial dimension had a Gaussian distribution as well with a 5% accepted variability across the identified dimensions.
  • Hydrogen was introduced into the chamber at a pressure between 1 to 10 bars and was absorbed by the rare earth containing materials within the chamber. This process of hydrogen absorption was initiated around room temperature (other initial temperatures are clearly possible, but accounting for the exothermic nature of the reaction) and was typically carried out for one to six hours. During the reaction, chamber temperatures typically rose to ⁇ 80° C. due to the exothermic nature of the reaction. Once the pressure was stable and the temperature returned to ambient, the reaction was considered complete.
  • the mixed coarse powders were then transferred to another rotating chamber for further mixing under partial vacuum ( ⁇ 210 mbar).
  • the resulting finer powders were then heated to 580° C. for 20 hours, while maintaining a partial vacuum. During the heating process, hydrogen gas was released from the material; the reaction was completed once the pressure stabilized.
  • the resulting mixed powder was discharged from the rotating reactor and passed through a 4-mesh screen. The particles that did not pass through the sieve were returned to the rotating reactor for recycling.
  • ICP inductively coupled plasma
  • the powder mix was then further homogenized by passing it through a jet milling apparatus using high pressure nitrogen or argon as the carrier gas, while the composition was periodically monitored by ICP.
  • a partially homogenized fine powder mixture having an average particle size in a range of from about 1 to about 4.9 micrometers and a particle size in which 99% of the material was able to pass through a 2500 mesh screen.
  • the powders were then transferred back to the particle homogenizing apparatus and mixed for another 45 to 60 minutes under partial vacuum or/and protective gas (Argon or Nitrogen) to achieve the final composition, which was confirmed by ICP.
  • the powder was characterized using a HELOS (Helium-Neon Laser Optical System) Particle Size Analyzer from Sympatec GmbH.
  • HELOS Helium-Neon Laser Optical System
  • the use of this instrument proved useful for this purpose but other methods may also be envisioned, for example, simple analysis by SEM particle counting.
  • the target properties were an average particle size of less than about 3.8 micrometers for 50% of the powder and less than about 3.9 micrometers for 90% of the powder by volume.
  • a mold was filled with the fine powder mixture at rate of 5000 grams/minute and a magnetic field was applied in such a way that the magnetic flux throughout the entire mold was 2.3 T. While the field was applied, the powder was pressed by a mechanical ram using a force ranging from about 1000 to about 2500 kN. In some implementations, the final green compact body had a density in a range of from about 4.3 to about 4.9 g/cm 3 , typically 4.6 g/cm 3 . In some cases, the oxygen concentration inside the pressing machine was below 200 ppm.
  • the pressing apparatus was controlled by a hydraulic servo technology, which yielded optimum accuracy of the applied force versus the aligning field. This apparatus was controlled by a PLC controller that allowed the press to yield a high degree of magnetic alignment. The weight consistency of the pressed parts was better than +1 wt %.
  • the green body was then subjected to a sintering heating regime ranging from about 1050 to about 1085° C. for 1-5 hours; typically about 1080° C. for 3.5 hours.
  • the sintering process was carried out under a combination of vacuum and argon pressure while sintering occurred.
  • this step was followed by an ageing/annealing treatment that kept the green compacted NdFeB type body at a temperature of 800° C. for 1-3 hours, (typically for 2.5 hours) and then at 520° C. for 1-6 hours (typically for 3.5 hours) under a combination of vacuum and argon pressure resulting in a final sintered permanent magnet, herein referred to as a GBE-NdFeB.
  • the oxygen content of NdFeB-based GBE-NdFeB was generally in a range of from about 500 ppm to about 2000 ppm.
  • NdFeB based GBE-NdFeB displayed a number of desirable properties, as shown in FIGS. 4 A-B .
  • Grain Boundary Engineering resulted in increases in coercivity up to 90%, with a minimal loss of remanence.
  • NdFeB-based GBE-NdFeB displayed enhanced corrosion resistance, and greater alpha and beta reversible coefficients, representing a greater resistance to demagnetization.
  • FIGS. 4 A-B presents a comparison between two sets of sintered magnets, referred to as the ‘Conventional Magnet’ and the ‘GBE-NdFeB Magnet’.
  • the Conventional Magnet was produced in the conventional way via strip casting using an alloy rich in the Nd 2 Fe 14 B phase.
  • the GBE-NdFeB Magnet was produced from the same starting material from which the Conventional Magnet was manufactured, however importantly contains a GBM alloy addition through the powder blending process described; such that there is a change in composition, as shown in Table 1.
  • a comparative flux ageing test was performed at various temperatures ranging from 20-200° C. on magnetic materials with and without the recited GBM alloy addition.
  • Two comparative samples were measured for magnetic flux by heating the sintered magnet body to various target temperatures and maintaining this target temperature for two and half hours while measuring the magnetic flux; after this measurement the temperature was increased for the next data point.
  • the magnetic characteristics of the samples are shown in table format in Table 7 and Table 8.
  • the results show the GBE-NdFeB magnet can have superior magnetic performance at elevated temperature with minor decreases in flux.
  • the conventional magnet in this comparison decreases more than 20% in flux at 120° C. while the GBE-NdFeB decreases less than 1%, demonstrating that high temperature stability can be increased by the addition of the GBM alloy.
  • Table 7A shows data for flux ageing experiments, comparing the conventional sintered NdFeB based magnet and a GBE-NdFeB magnet, compositions described in Table 7B. Measurements were made using a Helmholtz coils (model number HMZ 90540, made by Shanghai Hengtong HT magnet Company).
  • Table 8 shows resistivity and conductivity measurement information on a conventional sintered NdFeB based magnet and a GBE-NdFeB magnet.
  • the GBM alloy can modify the resistance and conductivity of strip cast material based on Nd 2 Fe 14 B.
  • the resistivity increases and the conductivity decreases by the introduction of the GBM alloy.
  • Electrical measurements were made using an HP 4192A LF Impedance Analyzer.
  • FIG. 5 shows an example of the microstructure of induction cast GBM alloy based on the previous methods, where a cross section was prepared by metallographic sectioning and polishing.
  • the microstructure shown was captured using a scanning electron microscope (SEM) in the back scattered electron imaging mode.
  • SEM scanning electron microscope
  • the resulting microstructure shows that the GBM alloy consists of multiple phases that appear in the SEM image as various levels of contrast.
  • the GBM additive was prepared using a 50 kg melt, based on the composition Nd 8.93%, Pr 3.05%, Dy 21.30%, Tb 21.16%, Co 38.33%, Cu 5.33% Fe 1.28%, Zr 0.62% by atom percent.
  • the specific chemical compositions of the areas marked 1, 2, and 3 are shown in Table 9.
  • B(T 1 ) and iH(T 1 ) are, respectively, remanence and intrinsic coercivity at temperature T 1 wheras B′(T 0 ) and iH(T 0 ) are remanence and intrinsic coercivity at the starting temperature T 0 but taken after cooling the specimens down.
  • the Grain Boundary Engineering process provided GBE magnets that exhibit better (lower) ( ⁇ ) in the range from 80° C. to 160° C., when compared to conventional magnet, with the improvement ranging from 70.2% at 80° C. to 16% at 160° C. (Tables 10-12). Note also that these improvements were observed despite the GBE magnet compositions having significantly lower Dy content (as much as 57.8 atom % less). In these experiments, the conventional magnets exhibited better performance above 180° C., which may have been due to the presence of up to 75% more Dy when compared to GBE magnets (see Table 12).

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Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11213890B2 (en) 2016-08-17 2022-01-04 Urban Mining Technology Company, Inc. Sub-micron particles of rare earth and transition metals and alloys, including rare earth magnet materials
JP2020504446A (ja) * 2016-12-23 2020-02-06 アーベーベー・シュバイツ・アーゲー 焼結磁石、電気機器、電気機器のための焼結磁石の使用、および焼結磁石の製造方法
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Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3802935A (en) 1972-05-25 1974-04-09 Geeral Electric Co Demagnetization of cobalt-rare earth magnets
DE19843883C1 (de) 1998-09-24 1999-10-07 Vacuumschmelze Gmbh Verfahren zur Wiederverwendung von Dauermagneten
WO2004029996A1 (ja) 2002-09-30 2004-04-08 Tdk Corporation Ｒ−ｔ−ｂ系希土類永久磁石
JP2004296793A (ja) 2003-03-27 2004-10-21 Kyocera Corp 太陽電池素子
US20040231751A1 (en) 2000-09-19 2004-11-25 Sumitomo Special Metals Co., Ltd. Rare earth magnet and method for manufacturing the same
US20070034299A1 (en) 2003-06-18 2007-02-15 Japan Science And Technology Agency Rare earth - iron - bron based magnet and method for production thereof
CN101026034A (zh) 2006-02-22 2007-08-29 南京理工大学 一种耐腐蚀稀土永磁材料的制备方法
CN101266855A (zh) 2007-12-29 2008-09-17 横店集团东磁股份有限公司 稀土永磁材料及其制造方法
US20090019969A1 (en) 2005-03-14 2009-01-22 Tdk Corporation R-t-b system sintered magnet
US20110052799A1 (en) 2008-02-20 2011-03-03 Hiroshi Nagata Method of recycling scrap magnet
CN102211192A (zh) 2011-06-09 2011-10-12 天津一阳磁性材料有限责任公司 二次回收料制备高性能钕铁硼的方法
CN102453804A (zh) 2010-10-20 2012-05-16 宁波科宁达工业有限公司 一种废旧镀镍稀土-铁-硼系永磁材料的再生利用方法
GB2487656A (en) 2011-01-24 2012-08-01 Univ Birmingham Magnet removal using hydrogen decrepitation
CN103117143A (zh) 2013-01-25 2013-05-22 宁波同创强磁材料有限公司 一种用钕铁硼镀镍废料烧结而成的钕铁硼磁体
US20140366687A1 (en) 2013-06-17 2014-12-18 Miha Zakotnik Magnet Recycling to Create Nd-Fe-B Magnets with Improved or Restored Magnetic Performance
WO2015002280A1 (ja) 2013-07-03 2015-01-08 Tdk株式会社 Ｒ－ｔ－ｂ系焼結磁石
WO2015020183A1 (ja) 2013-08-09 2015-02-12 Tdk株式会社 Ｒ－ｔ－ｂ系焼結磁石、および、モータ

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140066687A1 (en) 2012-08-29 2014-03-06 Source Production & Equipment Co., Inc. Radiation therapy of protruding and/or conformable organs

Patent Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3802935A (en) 1972-05-25 1974-04-09 Geeral Electric Co Demagnetization of cobalt-rare earth magnets
DE19843883C1 (de) 1998-09-24 1999-10-07 Vacuumschmelze Gmbh Verfahren zur Wiederverwendung von Dauermagneten
US20040231751A1 (en) 2000-09-19 2004-11-25 Sumitomo Special Metals Co., Ltd. Rare earth magnet and method for manufacturing the same
WO2004029996A1 (ja) 2002-09-30 2004-04-08 Tdk Corporation Ｒ−ｔ−ｂ系希土類永久磁石
JP2004296793A (ja) 2003-03-27 2004-10-21 Kyocera Corp 太陽電池素子
US20070034299A1 (en) 2003-06-18 2007-02-15 Japan Science And Technology Agency Rare earth - iron - bron based magnet and method for production thereof
US20090019969A1 (en) 2005-03-14 2009-01-22 Tdk Corporation R-t-b system sintered magnet
CN101026034A (zh) 2006-02-22 2007-08-29 南京理工大学 一种耐腐蚀稀土永磁材料的制备方法
CN101266855A (zh) 2007-12-29 2008-09-17 横店集团东磁股份有限公司 稀土永磁材料及其制造方法
US20110052799A1 (en) 2008-02-20 2011-03-03 Hiroshi Nagata Method of recycling scrap magnet
CN102453804A (zh) 2010-10-20 2012-05-16 宁波科宁达工业有限公司 一种废旧镀镍稀土-铁-硼系永磁材料的再生利用方法
GB2487656A (en) 2011-01-24 2012-08-01 Univ Birmingham Magnet removal using hydrogen decrepitation
CN102211192A (zh) 2011-06-09 2011-10-12 天津一阳磁性材料有限责任公司 二次回收料制备高性能钕铁硼的方法
CN103117143A (zh) 2013-01-25 2013-05-22 宁波同创强磁材料有限公司 一种用钕铁硼镀镍废料烧结而成的钕铁硼磁体
US20140366687A1 (en) 2013-06-17 2014-12-18 Miha Zakotnik Magnet Recycling to Create Nd-Fe-B Magnets with Improved or Restored Magnetic Performance
WO2014205002A2 (en) 2013-06-17 2014-12-24 Miha Zakotnik Magnet recycling to create nd-fe-b magnets with improved or restored magnetic performance
WO2015002280A1 (ja) 2013-07-03 2015-01-08 Tdk株式会社 Ｒ－ｔ－ｂ系焼結磁石
US20160086701A1 (en) 2013-07-03 2016-03-24 Tdk Corporation R-t-b based sintered magnet
WO2015020183A1 (ja) 2013-08-09 2015-02-12 Tdk株式会社 Ｒ－ｔ－ｂ系焼結磁石、および、モータ
US20160180993A1 (en) 2013-08-09 2016-06-23 Tdk Corporation R-t-b based sintered magnet and motor

Non-Patent Citations (10)

* Cited by examiner, † Cited by third party
Title
Firdaus et al., "Review of High-Temperature Recovery of Rare Earth (Nd/Dy) from Magnet Waste", Journal of Sustainable Metallurgy, Mar. 14, 2016, vol. 2, No. 4, 276-295.
International Preliminary Report on Patentability received for PCT Patent Application No. PCT/US2017/014488, dated Aug. 9, 2018, 16 pages.
International Search Report and Written Opinion received for PCT Patent Application No. PCT/US2017/014488, dated Apr. 20, 2017, 18 pages.
Kawasaki et al., "Reproduction of Nd—Fe—B Sintered Magnet Scraps Using a Binary Alloy Blending Technique", Materials Transactions, 2003, vol. 44, No. 9, 1682-1685.
Li Chao et al., "Waste Nd—Fe—B Sintered Magnet Recycling by Doping With Rare Earth Rich Alloys", IEEE Transactions on Magnetics, Dec. 1, 2014, vol. 50, No. 12, 1-3.
Merrow, "Estimating Startup Times for Solids-Processing Plants", Chemical Engineering, Oct. 1988, 89-92.
Uestuener et al., "Dependence of the Mean Grain Size and Coercivity of Sintered Nd—Fe—B Magnets on the Initial Powder Particle Size", IEEE Transactions on Magnetics, Oct. 2006, vol. 42, No. 10, 2897-2899.
Zakotnik et al., "Commercial-scale recycling of NdFeB-type magnets with grain boundary modification yields products with ‘designer properties’ that exceed those of starting materials", Waste Management, Oct. 1, 2015, vol. 44, 48-54.
Zakotnik et al., "Multiple recycling of NdFeB-type sintered magnets", Journal of Alloys and Compounds, 2009, 469, 314-321.
Zakotnik et al., "Possible methods of recycling NdFeB-type sintered magnets using the HD/degassing process", Journal of Alloys and Compounds, 2008, 450, 525-531.

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